Berdych came back to make it 5-5 but the left-handed Shapovalov then drew his opponent into the net and unleashed a wicked one-handed backhand passing shot down the line.

On his first match point, Shapovalov wrong-footed Berdych with another shot down the line that his opponent couldn't get back.

The risk-taking Shapovalov committed twice as many unforced errors as Berdych but also hit more than three times as many winners.

"I just couldn't find my footing the first set. The clay is so different here," said Shapovalov, who is making his Rome debut. "But I just kept fighting, kept competing. And I'm really happy I got to turn the match around."

On a day in which the start of play was delayed and then interrupted by rain, ninth-seeded David Goffin struggled to beat Italian wild card Marco Cecchinato 5-7, 6-2, 6-2 before a partisan crowd; 14th-seeded Diego Schwartzman eliminated Chilean qualifier Nicolas Jarry 6-4, 6-1; and 16th-seeded Lucas Pouille held off Italian wild card Andreas Seppi, 6-2, 3-6, 7-6 (3)

Greek qualifier Stefanos Tsitsipas, who reached the final of the Barcelona Open last month, advanced when Borna Coric retired while trailing 4-1.